\documentclass[tikz,border=2mm]{standalone}
\usepackage{array,amsmath,mathptmx,xcolor,bbding,pifont,colortbl,amssymb}
\usepackage[UTF8]{ctex}
\newcolumntype{C}[1]{>{\centering\let\newline\\\arraybackslash\hspace{0pt}}m{#1}}
% 只需要这个就可以
\usepackage[thicklines]{cancel}

% 可以设置线条颜色，默认是黑色
\usepackage{xcolor}
\renewcommand{\CancelColor}{\color{red}} 
\usepackage{tikz-cd}
\usepackage{tikz,graphicx,subfig,caption} % Required for drawing custom shapes
\usetikzlibrary{fit,matrix,chains,arrows,shapes,positioning,arrows.meta,chains,shadows,shapes.callouts,decorations.text,shapes.symbols,shapes.misc, positioning,decorations.pathreplacing,calc,backgrounds}
\arrayrulecolor{red}
% 设置浅蓝色
\definecolor{lightblue1}{RGB}{175, 175, 237}
\definecolor{lightgreen1}{RGB}{226, 246, 186}
\definecolor{lightpink}{RGB}{255, 202, 203}
\definecolor{lightblue2}{RGB}{205, 235, 255}
\definecolor{lightyellow}{RGB}{255, 254, 208}
% 设定删除线颜色
\renewcommand{\CancelColor}{\color{blue}}

\begin{document}
	\begin{tikzpicture}[>=latex,every node/.style={inner sep=0.2em}]
		
		\node[align=left] at (0,0) (point1){
			$\because$\hspace{0.5em}四元式结构:  \\
			\hspace{2em}quat(v$=$E)$=$  
		};
		
		\node[align=left] at ([xshift=2.5em,yshift=-1.5em]point1.south)(point3){
			\hspace{1.5em}quat(E),    \\
			q(\hspace{0.5em}$=$\hspace{0.5em}res(E)\hspace{0.5em}$\_$\hspace{0.5em}v\hspace{0.5em}).
		};
		
		\node[align=left,rounded corners=0.5em] at ([xshift=9em,yshift=-3em]point1.east) (point2){
			\hspace{0.3em}$\therefore$\hspace{0.5em}四元式:  \\
			(1)(\hspace{0.5em}$-$\hspace{1em}b\hspace{1em}c\hspace{1em}t1\hspace{0.5em})  \\
			(2)(\hspace{0.5em}$*$\hspace{1em}a\hspace{1em}t1\hspace{1em}t2\hspace{0.5em}) \\
			(3)(\hspace{0.5em}$+$\hspace{1em}d\hspace{1em}e\hspace{1em}t3\hspace{0.5em}) \\
			(4)(\hspace{0.5em}$/$\hspace{1em}t2\hspace{1em}t3\hspace{1em}t4\hspace{0.5em}) \\
			(5)(\hspace{0.5em}$:=$\hspace{1em}t4\hspace{1em}\_\hspace{1em}x\hspace{0.5em}) 
			
		};
		
		\begin{pgfonlayer}{background}
			\node [draw=black,fill=white ,rounded corners=0.5em,rectangle, inner sep=0.2em,line width=0.0025em][fit=(point2)(point1)](box1){};
			\node [draw=orange,fill=white ,dashed, rounded corners=0.5em,rectangle, inner sep=0.15em,line width=0.0025em][fit=(point3)](box2){};
		\end{pgfonlayer}
		% 大括号
		\draw[decorate,draw=orange,decoration={brace,raise=8pt,amplitude=5pt,mirror}] ([xshift=1em,yshift=3em]point2.west) --([xshift=1em,yshift=-3em]point2.west);
		
		% 箭头
		% \draw[line width=0.1em, -triangle 90, red, 
		% postaction={draw, color=white,line width=0.05em,shorten >=.1em,shorten <=.5em}]
		% (point3.east) -- ($(point1.east) + (0,-1.2em)$) -- (point2.west);
		\draw[line width=0.1em, -triangle 90, orange, 
		postaction={draw, color=white,line width=0.05em,shorten >=.1em,shorten <=.5em}]
		([xshift=-4.5em,yshift=0.8em]point2.west) -- ([xshift=-0.3em,yshift=0.8em]point2.west);
		\draw[line width=0.1em, -triangle 90, orange, 
		postaction={draw, color=white,line width=0.05em,shorten >=.1em,shorten <=.5em}]
		([xshift=-2.65em,yshift=-1.3em]point2.west) -- ([xshift=-0.4em,yshift=-3.7em]point2.west);
		
		
		
	\end{tikzpicture}
\end{document}